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x86/uaccess, ftrace: Fix ftrace_likely_update() vs. SMAP
[ Upstream commit 4a6c91fbde
]
For CONFIG_TRACE_BRANCH_PROFILING=y the likely/unlikely things get
overloaded and generate callouts to this code, and thus also when
AC=1.
Make it safe.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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1 changed files with 4 additions and 0 deletions
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@ -205,6 +205,8 @@ void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect)
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void ftrace_likely_update(struct ftrace_likely_data *f, int val,
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int expect, int is_constant)
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{
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unsigned long flags = user_access_save();
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/* A constant is always correct */
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if (is_constant) {
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f->constant++;
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@ -223,6 +225,8 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
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f->data.correct++;
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else
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f->data.incorrect++;
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user_access_restore(flags);
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}
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EXPORT_SYMBOL(ftrace_likely_update);
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